Final answer:
Trawling vessels display white lights and colored lights to indicate their fishing operations and ensure safe navigation. They may also use specific orange day shapes to indicate their activities during the daytime.
Step-by-step explanation:
Trawling vessels are boats used for commercial fishing, specifically for trawling. Trawling is a method of fishing that involves dragging a net through the water to catch fish or other marine organisms. Due to their nature, trawling vessels need to display certain lights and day shapes to indicate their activities and alert other vessels at sea.
A trawling vessel typically displays white lights, as well as colored lights, to indicate its fishing operations. These lights are used to warn other vessels of their presence and to ensure safe navigation. For example, a trawling vessel may display a white masthead light at the front, a white stern light at the back, and green and red side lights. These lights are similar to those used by other vessels to indicate their movements.
In addition to lights, trawling vessels may also use specific day shapes during the daytime. These shapes are typically orange in color and are placed where they are easily visible by other vessels. These day shapes indicate that a trawling vessel is engaged in fishing and help other vessels identify its activities.